Alloys



Patented Mar. 24, 1936 UNITED STATES PATENT OFFICE ALLOYS No Drawing. Application March 2, 1935, I

Serial No. 9,110

6 Claims.

My invention relates to alloys.

Applicant has found that ternary coppersilicon-tin alloys with a high copper content and the silicon and tin within certain ranges and proportions possess a high resistance to corrosion, a high tensile strength, and relatively high ductility or elongation in both the fully annealed and cold worked conditions, and that they may be heat treated when cold worked markedly to increase their yield point without reduction or marked change in tensile strength, ductility and hardness.

It has been found that if iron is added to these alloys the harness may be controlled both by varying the amount of iron and by heat treatment of the alloy without materially decreasing the resistance to corrosion or other properties of the alloy except a slight increase in tensile;

strength at the expense of a slight decrease in ductility.

Preferably the amount of iron is such in relation to the amount ,of silicon as to cause all the iron to be in the form of iron silicide, thus avoiding the presence of free'iron which otherwise would be present due to the insolubility of the iron in the copper-base. Any deleterious eifect on'the corrosion resistance of the alloy due to the presence of iron silicide and minute quantities of free iron is more than oflset by the tin. The iron silicide it has been found apparently dissolves in the fully annealed alloy, but precipitates in the heat treated alloy to form needlefike crystals which act to lock together the 'glide lanes of the crystals which act to' lock together planes of the crystals of the basic alloy. Thus in the fully annealed alloy the hardness is not materially aflected by the addition of iron to the basic alloy, but in the heat treated alloy the addition of iron secures a noticeable hardening eil'ect.

In the improved alloy, although the preferred range of silicon is approximately 2.75 to 3.5%, below which range the tensile strength and yield point increasingly decrease and above which range the alloy becomes increasingly diflicult to cold work, the silicon in many instances may be as low as 2% and still an alloy be secured which has the desired properties.

The alloy in respect to many of its properties is rather sensitive to iron, and ordinarily the latter should be maintained between approximately 0.1 and 0.6% so as not deleteriously to afl'ect the properties of the alloy. A preferred value of 0.25% iron ordinarily gives excellent results.

The preferred range of tin for the abovemem tioned preferred range of silicon is 0.25 to 0.5%, but by maintaining a proper relation between the tin and silicon the amount of tin in some instances may be materially increased. As little 5 as 0.25% tin may be present for all values of silicon from 2 to 3.5%, but to maintain the alloy hot workable within this range of silicon the tin should not exceed approximately 2% for 3% silicon and a progressively decreasing value as the silicon is increased or decreased above or below 3%. Approximately, with any value of silicon less than3%, the'amount of tin should not exceed a value which decreases linearly from 2% at 3% silicon at the rate of about 4% for The alloy may be fully annealed by heating it to about 1200 to 1300" F., and within the preferred range of 2.75 to 3.5% silicon, 0.25 to 0.5% tin, and 0.25% iron, all the alloys will have a tensile strength of at least approximately 60,000 pounds per square inch and an elongation of at least approximately 60% in two inches. These alloys may be cold drawn into rods having a tensile strength of at least'approximately 125,000 pounds per square inch and an elongation of at least approximately 9% in two inches,; and may be cold rolled into sheets having a tensile strength of at least approximately 115,000 pounds per square inch and an elongation of at least approx imately 4% in two inches. In general all the alloys within the larger ranges of constituents 40 above specified have a tensile strength of at least 58,000 pounds per square inch and an elongation of at least approximately 60% in two inches when in the fully annealed condition, and are capable of being cold drawn into rods having'a tensile cles. By heating the cold worked articles to 500 to 600 F. for 30 to 90 minutes and cooling them in air at room temperature the yield point and hardness of the alloy will be markedly increased and proportions: silicon 2 to 3.5%, tin 0.25 to 2%,

iron 0.1 to 0.6%, balance substantially all copper, the minimum amount of tin being 0.25% for all values of silicon, the maximum amount of tin CERTIFICATE OF CORRECTION.

Patent No. 2,035,414.

March 24, 1935.

RICHARD A. WILKINS.

5 without any material change in the tensile varying between 1.75 and 2% directly and linear- 5 strength and elongation. It will be observed ly with the amount of silicon when the latter is that this heat treatment is performed at temperbetween 2 and 3% and varying between 1.7 and atures below the full annealing temperatures, or, 2% inversely and linearly with the amount of in other words, is performed at temperatures besilicon when the latter is between 3 and 3.5%;

low the recrystallization temperatures of the copthe alloys being of relatively high tensile strength 10 per-silicon-tin solution, although performed at and. ductility in both the fully annealed and cold the temperatures at which dissolved iron silicide worked conditions, and when cold worked from will precipitate as has hereinbefore been rethe fully annealed condition being capable of beferred to. {I ing heat treated for markedly increasing both The alloys described, besides being capable of the yield point and hardness with but relatively 15 hot rolling and drawing enabling mill products small change in the tensile strength and dueeconomically to be fabricated of them, and capatility. ble of being cold rolled and drawn and otherwise 2. The alloys according to claim 1 having apcold worked, present superior alloys for welding proximately 0.25% iron.

purposes. 3. The alloys according to claim 1 having ap- 20 It will be understood that small amounts of proximately 2.75 to 3.5% silicon. metals other than those herein specified may be 4.- The alloys according to claim 1 having, apadded to the alloys for imparting special characproximately, 2.75 to 3.5% silicon and 0.25 to 0.5% teristlcs when these metals do not destroy such tin.

valuable properties of the alloy as it may be de- 5. The alloys according to claim 1 having, ap- 25 sired to retain. proximately, 2.75 to 3.5% silicon and 0.25% iron.

I claim: 6. The alloys according to claim 1 having, ap-y 1. Copper base alloys capable of being worked proximately, 2.75 to 3.5% silicon, 0.25 to 0.5% tin, both hot and cold containing copper, silicon, tin and 0.25% iron.

and iron within the following approximate ranges RICHARD A. WILKINS. 0

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 14, for "harness" read hardness; and lines 54 and 35,strike out the words "which act to lock together planes of the crystals"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 28th day of April, A. D. 1936.

Leslie Frazer Acting Commissioner of Patents.

(Seal) cles. By heating the cold worked articles to 500 to 600 F. for 30 to 90 minutes and cooling them in air at room temperature the yield point and hardness of the alloy will be markedly increased and proportions: silicon 2 to 3.5%, tin 0.25 to 2%,

iron 0.1 to 0.6%, balance substantially all copper, the minimum amount of tin being 0.25% for all values of silicon, the maximum amount of tin CERTIFICATE OF CORRECTION.

Patent No. 2,035,414.

March 24, 1935.

RICHARD A. WILKINS.

5 without any material change in the tensile varying between 1.75 and 2% directly and linear- 5 strength and elongation. It will be observed ly with the amount of silicon when the latter is that this heat treatment is performed at temperbetween 2 and 3% and varying between 1.7 and atures below the full annealing temperatures, or, 2% inversely and linearly with the amount of in other words, is performed at temperatures besilicon when the latter is between 3 and 3.5%;

low the recrystallization temperatures of the copthe alloys being of relatively high tensile strength 10 per-silicon-tin solution, although performed at and. ductility in both the fully annealed and cold the temperatures at which dissolved iron silicide worked conditions, and when cold worked from will precipitate as has hereinbefore been rethe fully annealed condition being capable of beferred to. {I ing heat treated for markedly increasing both The alloys described, besides being capable of the yield point and hardness with but relatively 15 hot rolling and drawing enabling mill products small change in the tensile strength and dueeconomically to be fabricated of them, and capatility. ble of being cold rolled and drawn and otherwise 2. The alloys according to claim 1 having apcold worked, present superior alloys for welding proximately 0.25% iron.

purposes. 3. The alloys according to claim 1 having ap- 20 It will be understood that small amounts of proximately 2.75 to 3.5% silicon. metals other than those herein specified may be 4.- The alloys according to claim 1 having, apadded to the alloys for imparting special characproximately, 2.75 to 3.5% silicon and 0.25 to 0.5% teristlcs when these metals do not destroy such tin.

valuable properties of the alloy as it may be de- 5. The alloys according to claim 1 having, ap- 25 sired to retain. proximately, 2.75 to 3.5% silicon and 0.25% iron.

I claim: 6. The alloys according to claim 1 having, ap-y 1. Copper base alloys capable of being worked proximately, 2.75 to 3.5% silicon, 0.25 to 0.5% tin, both hot and cold containing copper, silicon, tin and 0.25% iron.

and iron within the following approximate ranges RICHARD A. WILKINS. 0

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 14, for "harness" read hardness; and lines 54 and 35,strike out the words "which act to lock together planes of the crystals"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 28th day of April, A. D. 1936.

Leslie Frazer Acting Commissioner of Patents.

(Seal) 

